1. Field of the Invention
The present invention refers to a claw for a milking machine, comprising a housing, having a first portion and a second portion, at least one inlet member, adapted to connect the inner space of the housing to a teatcup of the milking machine, an outlet member, adapted to connect the inner space of the housing to a milk collecting member of the milking machine via a conduit member, and a distributing member comprising at least one inlet pipe arranged to be connected to said milking machine and at least one outlet pipe arranged to be connected to said teatcup, said outlet member being provided on the first portion and said inlet member being provided on the second portion.
2. Description of the Prior Art
One milking claw, known by EP-B-418 260, comprises a housing having a center axis, which in an operating position of the claw extends vertically, and an upper and a lower portion. The inner space of the housing forms a chamber for receiving milk via four inlet members connected to a respective teatcup of the milking machine. An outlet member, which via a milk conduit is connected to a milk collecting unit of the milking machine, extends from said chamber. Both the outlet member and the inlet members are fixedly provided on the upper portion of the housing and are thus not movable in relation to each other. The outlet member comprises an outlet nipple extending radially outwardly perpendicularly from the center axis of the housing. The inlet members comprise four inlet openings provided in pairs so that one of the pairs is intended to be connected to teatcups being applied to the front teats of the cow and the other pair is intended for teatcups being applied to the rear teats of the cow. The inlet members are provided on a conical surface of the upper portion at the same height with respect to the vertical center axis.
For such a claw the ideal operating position during milking of a cow is provided by an imaginary longitudinal center line between the inlet members for the rear teats and between the inlet members for the front teats as well as the longitudinal axis of the outlet nipple coincide, when seen from above, with a center line of the cow, which extends in the middle between the front teats and in the middle between the rear teats. However, this ideal operating position is never obtained in practice since the milk conduit connected to the outlet nipple and to a milk collecting unit located laterally of the cow, will apply a force tending to rotate the claw. Since the milk conduit is a relatively heavy and rigid transport hose, which in addition may be connected to one or several pulse conduits, the torsional forces acting on the claw in a horizontal direction as well as a vertical direction are significant. Such a rotation of the claw influences the position of the teatcups at the teats and may result in such a twisting or rotation of the teats that the teat cistern is constricted and that the extraction of milk from the udder is obstructed or even no longer possible.
In order to overcome this problem it has been suggested to introduce devices, for instance a so called service arm, keeping the claw and/or the milk conduit in a proper position. Beside the fact that such auxiliary equipment makes the milking plant more expensive, such devices are hindering and require additional work for attachment.
SE-B-449 154 discloses a milking machine having a claw comprising a housing with an upper portion and a lower portion. Four inlet nipples are provided on the upper portion and connect the inner space of the housing to a respective teatcup of the milking machine via conduits. Four outlet nipples are provided on the lower portion and connect the inner space of the housing to a milking collecting member of the milking machine via conduits. In the inner space of the housing there are four intermediate walls dividing the inner space of the housing in four chambers having an equal size. One inlet nipple and one outlet nipple is connected to each chamber. The upper portion may be rotated in fixed 90.degree. steps in relation to the lower portion so that each inlet nipple may be displaced to be opposite another outlet nipple.
DK-C-74799 discloses a claw having an upper portion in which four inlet nipples are provided and a lower portion comprising an outlet nipple. Furthermore, a distributing member is provided on the upper portion and comprises two inlet pipes to be connected to a milking machine and four outlet pipes arranged to be connected to a respective teatcup. Although the lower portion, the upper portion and the distributing member are rotatable in relation to each other, this known claw does not disclose the possibility of providing the inlet pipes of the distributing member in such a manner that they always will be directed in the same direction as the outlet nipple of the claw.
SE-C-133 288 discloses a claw having a lower portion with an outlet nipple provided to extend vertically downwardly and an upper portion having four inlet nipples.
SE-C-104 989 discloses a claw having individually movable inlet nipples. These are provided in an upper portion provided on a lower portion from which the outlet nipple of the claw extends.